Keyboard extenders for answering questions

The problem

Most non-trivial mathematical problems cannot be answered using the conventional QWERTY keyboard. Other programs that offer computer based tasks simply avoid the issue
by making the questions multiple choice, true/false, yes/no etc. Worse, some of them compromise pedagogy by simply not expecting complete answers from students, ignoring issues such as units, indices etc.

Arithmetika neatly solves the problem by giving students pop-up short-cuts to menus full of the necessary characters and symbols. There is one pop-up for each of

units of measurement

Rates

Indices

Mathematical symbols

Greek letters

How they work

Students click on an icon to bring up a list of the pop-ups, select the one they want and then click on the required characters. They are automatically added to the answer at the point of insertion and that's that.